The disclosure relates to boost converters, and in particular, to boost converters having self-adaptive maximum duty-cycle-limit control.
Unless otherwise indicated herein, the approaches described in this section are not admitted to be prior art by inclusion in this section.
Boost converters generate an output voltage Vout that is higher than an input voltage Vin by switching the boost converter at a fixed duty cycle. Achieving acceptable regulation by the boost converter can be difficult when the boost converter drives higher output loads at lower input voltages. This problem often occurs when the gain of the boost converter is high and has a large variation. For example, the input voltage Vin may vary from 2.5 Volts to 4.7 Volts, while the output voltage Vout is at 10 Volts (producing a gain of 2.12 to 4.0 by the boost converter).
Achieving acceptable reliability and acceptable spike levels can be difficult when the input voltage Vin is very close to the target output voltage Vout. In this instance, the duty cycle should be lower. Because the duty cycle is fixed, the possible maximum output voltage defined by the maximum duty cycle can be much higher than the target output voltage of the boost converter.